Studies on Alternaria blight of pigeonpea

Out of 106 genotypes only 7 genotypes viz., Path 402 , Path 407 , NDA-14-4, NDA-14-15, NDA-14-16, NDA-14-29, NDA-14-36 were resistant against A.tenuissima under artificial inoculation conditions by spraying inoculums. Seventeen plant extracts were evaluated in vitro and in vivo. The effectiveness of extracts increased with the increase of their concentration and maximum inhibition was recorded at 15 per cent concentration at 7 days of incubation in vitro. The complete inhibition in radial growth was obtained in Neem followed by Eucalyptus, Garlic, Mehandi, Ginger,Tulsi, Madar, Kaner, Onion, Lantana, Sadabahar, Ashok, Bael, Bhang, Clerodendron, Parthenium and Marigold. The disease incidence was not much reduced by Clerodendron, Parthenium and Marigold at 15% concentration at 60 days after spraying. The same trend was also found in per cent disease control. However, per cent disease control in between Neem and Eucalyptus; Garlic and Mehandi; Ginger and Tulsi ; Kaner and Onion; Lantana and Sadabahar; Bael and Bhang; Parthenium and Marigold were at par to each other. The The lower per cent disease control was found in Clerodendron, Parthenium and Marigold.